Although naltrexone has been shown to be a safe and effective aid to the drug free treatment of opiate, and more recently alcohol dependence, only a small proportion of those individuals who could benefit from this medication have tried it. With the increasing number of individuals who are being arrested because of drug related crimes and the external pressures from the legal system to remain abstinent, this corrections population of former opiate dependent individuals is one group who could especially benefit from naltrexone treatment. Preliminary work with the United States Federal Probation Offices revealed that individuals who received naltrexone over a six month period had an overall rate of 8% opiate positive urines compared to an overall rate of 30% for individuals not receiving naltrexone. Furthermore, only 26% of those who took naltrexone had their probation revoked within the six month study period compared to 56 % of the control group. The proposed project is an extension of this prior study which included only 51 subjects, the majority of whom were men. The proposed project will examine the short and longer term effectiveness of naltrexone treatment in reducing opiate and alcohol use and reducing recidivism in parolees. We will also explore the relationship of psychopathy to naltrexone treatment response. The project will include 150 men and 50 women parolees with a history of opiate use assigned to the Philadelphia Forensic Intensive Recovery (FIR) program. Subjects will be randomly assigned to receive naltrexone treatment or no naltrexone treatment for a period of six months. They will be asked to come to our Center twice a week during the first six study months to meet with clinical and research staff. If they are assigned to the naltrexone group, during these meetings they will be administered naltrexone and discuss any side effects they may be having with the research physician. Those assigned to the control group will attend an equivalent number of counseling sessions. During these meetings all subjects will provide a urine sample and will complete self report questionnaires related to their craving state for opiates and alcohol their involvement in illegal activity, and use of treatment services over the prior week. Subjects in both groups will be followed at six month intervals from the time they entered the project for a period of two years. Each follow up -assessment will consist of comprehensive interviews concerning, employment, drug/alcohol use, and illegal behavior. Additionally, breathalyzer and urine drug screens will be performed at each follow up. Throughout the course of the study criminal records of participants will be monitored with the help of FIR.